Numerous skincare products have been developed for improving the appearance of human skin. Many of the more effective methods employ topically applied compositions containing one or more active ingredients known to beneficially affect the skin. For example, compositions containing retinoids, particularly retinol, have proven to be effective in combatting fine lines, wrinkles and other indications of skin aging such as sagging. Topically applied retinoids promote the formation of collagen and elastin in the skin. Compositions having retinoids may be used to treat a myriad of unwanted skin conditions, such as acne and wrinkles. However, the benefits of retinol therapy are known to plateau with prolonged use in some individuals.
Phytol is another active agent that is known to promote skin health and remediate or diminish signs of skin aging. A composition for enhancing the appearance of skin comprising both phytol and retinol is described in U.S. Pub. 2003/0198657 to Menon, the disclosure of which is hereby incorporated by reference herein.
It has been recognized that skin may become accustomed to cosmetic products, and the observable benefits to skin may begin to decline after an initial period of treatment. It has also been observed by dermatologists in clinical trials that skin can build up a tolerance to retinoids, and using higher concentrations of retinoid-containing compositions over time might be needed to maintain the desired effectiveness in some individuals. This phenomenon is analogous to adaptation, which is well-described in biological systems. For example, on a cellular level, stimulation of receptors leads to desensitization and a decreased response. A period of resensitization or “rest” is needed before the same level of response can be seen again.
It is therefore an object of the present invention to provide methods of treating skin that overcome the tolerance problem and/or provide enhanced efficacy and/or improve the health and/or appearance of human skin. It is a further object of the present invention to provide treatments for human skin involving the rotational, serial and/or alternating use of at least two distinct treatment modalities. It is a further object of the present invention to provide methods for improving the health and/or appearance of human skin involving the rotational, serial and/or alternating topical application of at least two skincare compositions.
The foregoing discussion is presented solely to provide a better understanding of nature of the problems confronting the art and should not be construed in any way as an admission as to prior art nor should the citation of any reference herein be construed as an admission that such reference constitutes “prior art” to the instant application.